There is an adage with regard to pines: "Only one insult per year." Apparently I should have heeded that better, because this pine is dead. I accepted the obvious today.
It never broke any new buds this spring, and the foliage it had slowly died off. The bark has that sunken-and-dried look that follows death of the cambium. An autopsy this weekend will see how much the roots recovered last season, if at all.
I thought a JBP was tough enough to take serious root pruning and serious top pruning in one season, but evidently I was mistaken. From now on -- "only one insult per year!"